Known from U.S. Pat. No. 4,653,489 is a system wherein fixation cement is introduced through a screw into a portion of a bone afflicted by osteoporoses. Femoral neck fractures as well as distal femoral fractures can be fixated by means of this device.
The system in accordance with prior art comprises a screw having a flow cavity, i.e. an axial through-bore through which bone cement can be introduced into the portion at the tip of the screw. The bone cement is advanced by a device which is releasably attached to the subsequent end of the screw. This device is similar to commercially available syringes. In use of this prior art device, the fixation cement is injected in an already fluidized state into the axial through-bore of the screw. Due to the pressure, the fixation cement is adequately fluidized, so that it can pass through the trailing end of the screw into the bone, as a result of which the screw is augmented in the bone.
This system has a drawback that the distribution of the fixation cement within the portion of the bone is neither reliable nor sufficiently controllable. It is in particular a drawback that the implant together with the fixation cement may shift within osteoporotic bone tissue as soon as forces apply onto the bone and thus onto the implant.